A main source of the party’s success is its insurgent flavour – pitching itself to disgruntled voters as outsiders pushing commonsense ideas while shunning Westminster’s polished methods. The popularity that approach has delivered now poses a new challenge: to grow further and capitalise on the poll figures, UKIP needs to professionalise, but without appearing to mimic the “LibLabCon” it loathes so much.

This causes some angst within UKIP’s ranks. Speaking to me recently, a senior member of the party drew a telling comparison: “Not long ago, we were running adverts saying the other parties were run by kids who hadn’t had proper jobs, now we’re hiring people exactly like that”. Others fear constant criticism of some of the party’s more loopy members (Henley’s sexuality meteorologist, for example) risks frightening the leadership away from political incorrectness.

One attempt to professionalise while retaining their radical roots comes in the form of Patrick O’Flynn. Next week he officially departs as the Chief Political Commentator of the Daily Express to become UKIP’s new Director of Communications – an employee of the party for which he is already standing in the European Election.

It isn’t rare for political journalists to move into political PR. Guto Harri left the BBC to work for Boris; Craig Oliver went to Downing Street after 19 years as a broadcast journalist and has now been joined by Graeme Wilson of The Sun; while Ed Miliband employs three former lobby journalists – Bob Roberts (Daily Mirror), Patrick Hennessy (Sunday Telegraph) and Tom Baldwin (The Times).

O’Flynn is the first to decide UKIP represents the next step in his career.

Patrick has always been an early adopter. In a political village full of received wisdom, he has a track record of sticking his neck out.

He picked up the issue of the inheritance “Death Tax” long before Osborne realised its potency, he was instrumental in giving the TaxPayers’ Alliance (TPA) some of its first national media coverage, he spoke up for the “squeezed middle” years before Miliband tried to adopt them and, most recently, he persuaded the editorial team at the Daily Express to make it the first national newspaper to support leaving the EU.

As Matthew Elliott, founder of the TPA, victor of the AV referendum and now Chief Executive of Business for Britain puts it:

“Patrick is superb at spotting hot issues before they hit the radar of the Westminster bubble. His role coordinating the Daily Express’s campaign against inheritance tax culminated in George Osborne making it a big issue and stopping an early election in it’s tracks. He also understood from TPA polling in 2008 that the EU was set to become a big issue and that voters wanted their say in a referendum. His political radar alone will be invaluable to UKIP.”

I remember the 2008 meeting between the TPA and O’Flynn that Matthew mentions. Patrick felt that the EU was harmful, but was sceptical of the Better Off Out position ever becoming a majority view. It seems his research into the subject led him inexorably towards the conclusion that we have to leave – and that it can be done. It must have fitted well with his sense that the people are ahead of the curve, and the politicians behind it – on the EU, as with the Death Tax before it, opinion polls suggest he was right.

While the subjects of his iconoclasm have varied, there’s a coherent theme – a deep suspicion of the Establishment and any consensus it might declare.

Growing up in an unpolitical household in Cambridge, as a comprehensive-educated teenager he took a strong interest in politics. He went on to study Economics at Cambridge University (where, coincidentally, he was mates with David Laws) and – according to friends – was not a socialist, but wasn’t won over by Mrs Thatcher either. Though he showed some interest in the SDP, perhaps foreshadowing his support today for another party that seeks to break the Westminster mould, he never carried anyone’s card – until now.

What could have persuaded an experienced, cynical political journalist, who had spent years involved in Westminster without feeling attracted to any party, to persuade his paper to support one, sign up as a candidate and then go to work for them full-time?

Prominent backers can be risky, as UKIP found out to its cost with Robert Kilroy-Silk. But with a suspicion of Westminster consensus, and anger about the neglect of hard workers in favour of “the fat cats at the top and…a chronically dependent underclass at the bottom”, O’Flynn seems a good fit with what they feel they are about.

Those around him say the feeling is mutual. “He seemed enthralled,” says one in attendance at O’Flynn’s first UKIP conference, “to have found somewhere he could comfortably hang his coat.”

It will be interesting to see how his arrival as a UKIP staffer changes his party’s messages. The tightrope between insurgency and professionalism is not their only challenge.

Over the last 18 months their membership has almost doubled – meaning that new recruits, often unacquainted with political activism or with the internal politics of their new party, may well outnumber the long-suffering hardcore who kept it going for the previous two decades.

It will be O’Flynn’s task to give those troops the right messages to deliver, to help Farage ride out the inevitable stories of activists saying odd or unpleasant things and, I suspect, to act as an informal mentor some of the less experienced staffers who now make up the UKIP team.

“For the first time in UKIP’s history, Farage is actively putting forward a range of his colleagues for presentation to the public…The prospect of UKIP developing a slate of viable, effective spokespeople rather than simply relying on their leader would have been unthinkable three or four years ago. Doing so makes them more successful as a party, appealing to different demographics and covering more ground as a team.”

It’s notable that many of those new faces of UKIP – and perhaps almost half of its MEP candidates – are now employees of the party in one way or another. O’Flynn is the latest – others work for MEPs, or in the central operation, or for the EFD group in the European Parliament. The professionalisation of UKIP is quite literal, not simply a change in tone.

Farage’s newfound willingness to allow others into the limelight is undoubtedly a symptom of his realisation that his party can’t rely on him forever. A number of those I spoke to suggested O’Flynn might be an effective successor were Nigel to fall under a bus: “Less pazazz – but while others are full of themselves, he could cut the mustard”, one said.

Those close to O’Flynn seemed genuinely surprised at the idea. “I doubt he has any desire for it”, one told me, pointing out that he had never stood for anything before he decided to put himself forward for the Euros. But with others tipping him for the job, he’s worth watching.

He may not have stood for election before, but when he finally chose to, UKIP’s members voted him top of his regional list – even above a sitting MEP. In short, Patrick O’Flynn is not an opponent to be dismissed lightly.